Calling on the geniouses of valveless...

[Gun Freak]

How does this look for a valveless gun, it will be blowgun fed from the back with about a foot of 3/4" pvc for the chamber which will be filled with bb's. Blue is 1/2" pvc sleeved over an airsoft barrel. The yellow is brass male x female adapters in 3/8". The nipple in the back is 3/8" close and goes to the chamber. What should I improve or is it the right idea?

[POLAND_SPUD]

Make sure that the bbs won't clog up just behind the detent. I suspect that 99% of feeding problems I had on mine were casued by that

Either use smaller fittings (with ID as close to 6mm as possible) or larger ones.

[Gun Freak]

Make sure that the bbs won't clog up just behind the detent. I suspect that 99% of feeding problems I had on mine were casued by that

Either use smaller fittings (with ID as close to 6mm as possible) or larger ones.

Hmm... I went up to 3/8" because I figured that they would have about the right diameter for the right washer with a big enough hole. It might be possible with 1/4" though. I have to see. 2 bb's can't fit through a 1/4" galvanized nipple side by side, but I think they can in 3/8".

[lozz08]

My mag fed valveless used 1/4 inch and the washer ID was 6mm exactly before compression. I suggest 1/4 because there is a good chance that the washer will be too large.

If it's going to be cloud style with a chamber full of bbs then it will jam unless the transition from the 3/4" pvc to the fitting is gradual. I suggest getting some epoxy putty and using it to make the end of the brass fitting that goes into the chamber flared.

There are a bunch of ways you could do it but just make sure theres no sudden edges for bbs to jam into. In fact i would say 3/8 inch fittings could cause jams because the ID of the fittings is so much larger than the bbs.

[Gun Freak]

Cool, making a funnel in the chamber should be pretty simple. I'll go with 1/4", if I can find the right washers. The chamber won't be completely full of bb's. I want room for them to fly around so they don't jam and also to make more chamber volume. Thanks for the help.

[POLAND_SPUD]

ohh I was thinking about this yesterday but I forgot to post here. yeah 3/8" might be a bit too large. It might not be such a big deal if you used a 3/8" pipe nipple to keep the washer in place but it seems that what lozz08 has said makes sense